Date of Award

Summer 8-18-2023

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Chemical Engineering

Advisor

Peter Van Walsum

Second Committee Member

Sampath Gunukula

Third Committee Member

M. Clayton Wheeler

Abstract

In this investigation we propose a novel method to enable precipitation of desired solutes using photo-isomers in the extraction solvent. This photo-switchable solvent would enable dissolution or precipitation of desired components using alternating UV or visible light to modify the solubility of the compounds of interest. Three photo-isomers namely native azobenzene, diethoxy azobenzene and diethylamino azobenzene were studied in three different organic solvents: medium chain length alcohol, ethanol and acetone. It was found that among the different combinations of solvent and photo-isomer, acetone and the 4,4’-diethoxy azobenzene solution was most efficient at precipitating dissolved lignin in response to UV light exposure. This system was able to precipitate 20% of the initial amount of lignin added.

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